The compounds of formula (II) or (II′), as defined below, can be useful as perfuming ingredients or as starting material for the construction of compounds having a more complex skeleton.
The methods of preparation of said compounds reported in the prior art are in general quite long and expensive. Moreover, each of said methods allows to obtain only one or the other of said compounds. Consequently, to obtain said compounds a person skilled in the art has to carry out two separate processes with an evident loss of time.
It is therefore highly desirable to access such compounds by means of a simple and efficient isomerisation process wherein the starting material is an easily accessible material and it is possible to obtain both compounds (II) and (II′).
To the best of our knowledge, in the prior art there is no report of an isomerisation process giving a direct access to compounds of formulae (II) and (II′) at the same time.